More Problems Undervolting 8600M GT

In order to decrease the heat output while gaming, I decided to undervolt my 8600M GT.

After flashing the GPU with a custom BIOS from Nibitor (voltage change from 1.2V to 1.1V max), I noticed no temp difference.

Eventually, I had undervolted all the way down to 1V (yes, from 1.2), and still no temp decrease (100% stable also).

This leads me to believe the the voltages Nibitor is reading/flashing are lies. I am sure I flashed correctly, since when I read the new bios to Nibitor, it shows the custom voltages...

...any thoughts? kinda hit a dead end here...

EDIT: Have undervolted all the way down to 0.8 V, when I reread the updated BIOS to Nibitor, it confirms this voltage. How is this possible while it is clocked at 550, 1100, and 433?

 

which utility did you use to monitor gpu temps?

 

the nvidia monitor...you think thats it?

 

Update: BIOS level overclocking seems to work, but voltages never have any effect.

 

Some manufacturers limit the allowable voltages. For example, my old 8800M GTX was clocked and volted at 700/1250/800 @ 1.0v. I could take it to 1.05v, which would allow a far higher overclock, and would increase heat. However, anything above 1.05v it would technically set at, but because my manufacturer (Clevo) set a limit on voltage, I could not go above it. The same thing applied for dropping down to .7v for underclocking. Anything lower would not make a difference at all.

Our cards are very different, but I assume the same principles apply.

 

Thanks, I guess I'll just try going lower...

In any event, if I get a BSOD or no screen I will just reflash to default.

 

If you get no screen, you have to blind flash. I had to do that once. As onlg as you use zFactor's guide for booting to usb, you'll be fine.

Just make sure you memorize what you do to go from hitting to power button on to typing the command to flash, cuz you might have to do it without a monitor.

 

Are you sure you're testing the correct way? If you're only lowering 3D voltages you'll only get lower temps/power consumption in games/3Dmark; if you're only lowering 2D you'll only get lower temps/power consumption out of games.

Maybe if the Throttle voltage is greater than the 3D one it defaults to the Throttle one?

Couldn't hurt to try a different hardware monitor as well - HWMonitor 1.10 would be a good one as it records the maximum temperature reached.

And temperature differences may only be a few degrees - the bigger difference might be in power consumption. Gaming on battery with other conditions as equal as possible may be the best test, although even then the difference probably won't be night and day, as you'll have the CPU chomping up tons of power usage while gaming as well.

Glad to hear it's worked well so far though. 1V is quite a drop, I'm not sure trying to go much lower is exactly advisable. You'll probably get a blank screen before a Blue Screen.

 

I just really question your monitoring program. I use gpu-z to see temps and its been really accurate.

 

I'll try GPU-Z, does it have a history line of recent temps, or a max recent temp?

By the way, I undervolted all the way down to .8V, and it is 100% stable, and actually SEEMS a little cooler, although I haven't tested extensively.

By the way, its overclocked 550, 1100, 433.

Personally, I don't think this should be possible.

 

nice undervolt! but have you checked performance to see if theres any change with the new undervolt?

 

I would run rivatuner's montior in the background, it will give you a nice graph of temps.

I may try this for my 8800M if I can somehow get the BIOS copied.